Abrar M. Khan

Effect of organic amendments on the growth and chemical composition of tomato, eggplant and chilli and their susceptibility to attack by Meloidogyne incognita.

SummaryFewer larvae ofMeloidogyne incognita invaded and fewer galls were formed when seedlings of nonresistant varieties of tomato, eggplant and chilli were growing in soil to which oilcakes of mahua, castor, neem/margosa, mustard and groundnut had been added. Chemical analysis of plant tissue showed that, compared with untreated plants, plants growing in treated soil contained greater concentrations of phenols and frequently of amino acids, proteins and carbohydrates.

Paurodontella n.gen. and three new species of nematodes from North India (Nematoda: Neotylenchidae).

Paurodontella minuta n. gen. n. sp. is proposed based on its short and robust body, short, convexconoid, ditylenchoid tail and long stem-like extension of the basal oesophageal bulb projecting into the intestine. Paurodontus apiticus Thorne, 1941, P. niger Thorne, 1941 and P. densus Thorne, 1941, are transferred to Paurodontella n. gen. Boleodorus typicus n. sp. is described and is distinctive in possessing six incisures in the lateral field. Basiliophora propora n. sp. is also described and is distinctive in its anteriorly located vulva.

Seinura propora n.sp. and Aphelenchoides aligarhiensis n.sp. (Nematoda: Aphelenchoididae) from North India.

Seinura propora n. sp. has an excretory pore in the region of metacorporal swelling, 2-3 rows of oocytes in the ovary and the vulva at 79-80 percent of the body length. Aphelenchoides aligarhiensis n. sp. has a stellate mucro on the tail tip and, as compared to A. asterocaudatus Das, 1960, has a shorter spear, longer post-uterine sac and males.

Three new species of Nothotylenchus (Nematoda: Neotylenchidae) from North India.

Three new species of Nothotylenchus viz., N. cylindricus n. sp., N. allii n. sp., and N. hexaglyphus n. sp. are described from Indian soils. N. cylindricus is distinctive in possessing an elongate cylindroid basal oesophageal bulb, thin-walled, oval spermatheca with spheroidal sperms and longer than head-width spear, while N. allii is characterized by its pyriform basal oesophageal bulb, four incisures in the lateral field and bursa enveloping only 2/5 of the tail. Nothotylenchus hexaglyphus can be differentiated by its poorly knobbed spear, set off pyriform basal bulb, posterior vulva, short postvulval uterine sac and lateral field with six incisures. A key to the species of the genus Nothotylenchus is presented.

Heterodera Mothi N. Sp. (Tylenchida: Heteroderidae) Parasitising Cyperus Rotundus L. At Aligarh, U.P., India

Heterodera mothi n. sp. from the roots of Cyperus rotundus at Aligarh, India is described and figured. The hyaline part of the larval tail is twice the stylet length.

Properties and nature of inhibitors of potato virus X in four medicinal plant extracts

The inhibitors present in the extracts ofCinchoma ledgeriana, Emblica officinalis, Chrysobalanus C. icaco andTerminalia chebula were heat-stable, resistant to autoclaving, aging and desiccation for a week. However, they did not withstand dialysis for 48 hrs (exceptT. chebula extract.) These four extracts markedly inhibited the virus even on dilution in the ratio of 1⤜1 but viral infectivity was sharply reduced at higher dilutions in each case. Moreover, the inhibitors in the stem bark extract ofC. ledgeriana, fruit pericarp extract ofE. officinalis andT. chebula were highly inhibitory even at pH 10·0, whereas inhibition of the virus by leaf extract ofC. icaco was reduced to 24 per cent only at the same pH. The inhibitors in these four extracts were found to be probably not proteinaceous in nature, when precipitated with ammonium sulphate and ethanol.AbstractV eextraktech zCinchonaledgeriana, Emblica officinalis, Chrysobalanus icaco a Terminalia chebula byly nalezeny termostabilní inhibitory, odolné vůči autoklávování a stálé i při vysýchání po dobu jednoho týdne. Tyto čtyři extrakty inhibovaly viry i při zředění 1⤜1 a virová infektivita byla výrazně snížena při vyšším zředění. Inhibitory z kůry kmene uC. ledgeriana a z perikarpu plodů uE. officinalis aT. chebula byly značně inhibiění i při pH 10,00 zatímco virální infektivita listových extraktů uC. icaco byla redukována při tomto pH na 24%. Předpokládáse, že inhibitory jež je možeo srážet síranem amonným a ethanolem nejsou bílkovinné povahy.

Basirotylept Us Modestus N. Sp. and Two New Species of Dorylaimoides Thorne & Swanger, 1936 From India

Three new species of soil nematodes are described and figured. Basirotyleptus modestus n. sp. is characterized by the labial disc, basal bulb equal in length to body-width and long anterior uterine sac. Dorylaimoides leptus n. sp. is distinctive in possessing post-anal intestinal blind sac, smooth inner part of cuticle, asymmetrical gonads and elongate-conoid, dorsally bent tail and D. elongatus n. sp. is distinctive from its closest relative D. modestus by its offset lip region, its vulva position and basal bulb length.

Effect of carbon sources on germination of chlamydospores of Ustilago scitaminea Syd

SAXENA 6: KHAN (1963, 1964) have reported that the chlamydospores of different collections of Ustilago scitaminea SYD. differ both in their percentage and rate of germination at various temperatures and relative humidity. Smut fungi also vary in their nutrient requirements. BREFELD (1905), for the first time, noted that the spores of some smuts either exhibited poor germination or no germination at all in water, while excellent germination took place in nutrient solutions. STAKMAN (1913), on the other hand, found that with the exception of soil infusion, nutrient media seemed to affect adversely the spore germination. RABIEN (1927) reported that dextrose and cane sugar reduced the germination of Tilletia caries (DC) TUL., and T./oetida WALLR. and that there was no germination in 0.1 per cent peptone solution. KIENHOLZ 6: HEALD (1930) reported the unsuitability of the rich media for spore germination in bunt fungi. LOWTHER (1950) confirming the findings of KIENHOLZ 6: HEALD found that rich media tended to reduce the germination of chlamydospores of T. caries and T. /oetida. KERNKAMP (1939, 1942) reported that chlamydospores of Ustilago zeae (BECK.) Unger germinated by the formation of a fourcelled promycelium which either bore sporidia or produced hyphal branches. He claimed that this behaviour of chlamydospores is influenced by the environmental factors in this smut. He further stated that higher sugar content stimulated sporidial formation. These contradictory reports may probably be due to the fact that very few carbon sources were tried by the previous workers in their tests. It is, therefore, evident from the foregoing that nothing is known regarding the effect of different carbon sources on the germination of chlamydospores of U. scitaminea. Hence an attempt has been made to determine the effect of eleven different carbon sources

Fungi associated with sorghum seeds.

A study of the external and internal fungi associated with different varieties ofSorghum seeds has been made. The varieties tested included eighteen local varieties and twelve newSorghum varieties obtained from the Rockefeller Foundation. The external fungi were studied by preparing suspensions of superficial fungi and growing on potato dextrose agar. The internal fungi were studied by planting surface sterilized seeds on P.D.A. and pure cultures of all these fungi were prepared. The external fungi found to be associated with the different varieties included different species ofPhycomyces, Circinella, Syncephalastrum, Chaetomium, Curvularia, Cladosporium, Helminthosporium, Montospora, Pullularia, Aspergillus, Penicillium, Cephalosporium, Trichoderma, Phoma, Fusarium. The internal fungi recovered from these varieties included species ofChaetomium, Cladosporium, Curvularia, Helminthosporium, Heterosporium, Hormodendron, Pullularia, Alternaria, Aspergillus, Blastomyces, Monilia, Penicillium, Fusarium, Phoma, Phomopsis. Varieties 4403B, 1060 and 503 were found to carry a large number of fungi. Variety Black spanish was found to be entirely free from any internal or external fungus. Varieties which were free from endophytic fungi but possess external fungi only were Kaoling 301, African variety 901 and Shallus 475. Three fungi viz.,Pullularia, Heterosporium, Monilia have been recovered from theSorghum seeds for the first time.

A simple device for collecting root exudates chromatographic studies

SummaryA simple apparatus is described for the collection of root exudates at different intervals without disturbing the root system of the seedling.